Percutaneous nephrolithotomy (PCNL) is a well-established treatment modality for renal stones. It offers a high stone free rates and less invasive than open surgery. Nevertheless PCNL is an invasive and technically demanding procedure with inherent risks and complications. The most troublesome morbidities are bleeding and injury to the kidney and its adjacent structures. Complications of PCNL tend to be associated with the accuracy of tract placement and the size of the nephrostomy tract. To improve the safety of PCNL, there is a trend toward using smaller and smaller nephrostomy tracts . With the smaller nephrostomy tract, there also arise the problems of compromised visual field and increased difficulty in stone extraction. Increase irrigation using pressure pump might improve the visualization and the passive egress of the stone fragments, but it also may concomitantly increase the intra-luminal pressure.